This application relates to a landing gear for an aircraft wherein braking is provided with both electric motor/generator and eddy currents induced by rotating permanent magnets and high electric conductivity stationary disks.
Aircraft are typically provided with landing gear which include wheels that touch the ground and roll as the aircraft begins to slow and eventually stop. In the past, systems have been proposed that include permanent magnet disks associated to rotate with the wheel, and electromagnetic disks provided with a stator hub and fixed adjacent to the disks on the wheel. Electromagnetic disks contain polyphase or single phase coils.
A control system controls the electromagnetic disks, and is able to provide drive for the wheel such that the wheel can move up to the speed of the aircraft just before touchdown to reduce friction. The electromagnetic disk-permanent magnet system operates as a motor. After touchdown, the electromagnetic disk-permanent magnet system operates as a generator producing a retarding force, such that it assists in braking the wheel, and is utilized in conjunction with mechanical brakes. The electric energy produced upon landing can be regenerated/stored for later use by the aircraft power system or dissipated through a resistor.
Such systems are disclosed in prior U.S. Pat. Nos. 7,226,018, and 7,237,748, the description of which is incorporated by reference here.